The Director of the Science Museum Group, the London-based body responsible for Manchester's Museum of Science and Industry, the National Railway Museum in York and Bradford’s National Media Museum, has confirmed that closing one of the three northern sites is a "real threat" ahead of another painful round of government spending cuts.

An initial budget reduction of 25% was imposed after the Coalition government’s election in 2010. But the next spending review, which will be announced at the end of the month, is expected to tighten funding by a further 10%.

Speaking on BBC Radio 4’s The World at One programme, Ian Blatchford said leaders were contemplating closing the doors to one of the venues “with a very heavy heart”.

“We’ll end up with a deficit of about £6 million per year, which for a museum is a huge amount of money,” he elaborated.

“We really, really are looking at it – this is not some kind of fake exercise.

“The cuts as scheduled are so significant that these threats are real.”

The Media and Railway museums responded to supporter concerns by stressing that no decisions had been made, adding that plans to reduce their costs are already being formulated.

In Manchester, more than 20,000 people have already signed several petitions launched to oppose any closure of the MOSI.

“We will not stand down and let this happen,” wrote one of the signatories.

“Manchester is the centre of the Industrial Revolution in this country, and it isn’t seen to be valuable enough to have a site educating people about this.”

“It is an essential part of Manchester,” said another.

“I am sick and tired of London being made the priority at the expense of other places. This is outrageous.”

Blatchford said organisers “do not have the power” to introduce admission charges at the venues under the terms of the 2001 agreement which made entrance to all national museums free.

The move saw visitor numbers to the MOSI treble, with more than 830,000 people passing through the former railway setting last year.

MPs, Trade Unionists and local residents joined scientist Professor Brian Cox and musician Clint Boon in a Manchester Evening News campaign against the plans which added more than 6,000 petitioners overnight.

“I think what that tells you is how much people adore these museums,” said Blatchford.

“[The MOSI] has the most enormous potential.

“Although it may seem shocking that there is this great furore and passion about saving it, it tells you that people really care about their museums.”

Calling York, Bradford and Manchester “three great cities with very different economies”, Blatchford said no conclusions had been drawn surrounding which museum stood at the greatest risk.

The Group, which also co-ordinates the Science Museum in London, may be transferred from the Department for Culture, Media and Sport to the Department for Business, Innovation and Skills in an attempt to safeguard its future.

But there were fears in Bradford that the National Media Museum could be the venue chosen if a closure is on the cards.

“Bradford is the most expensive one and I don’t think they will move York or the well-established one in Manchester,” Bradford South MP Gerry Sutcliffe told the Telegraph and Argus newspaper.

“To lose the museum would be a catastrophe.”

Bradford West MP George Galloway called the museum “a timeless and unique cultural artefact.”

“This cannot be about cash,” he argued.

“It’s about heritage and hope for the future.

“If the city centre is to revive, it is vital that investment is put into establishing a cultural quarter in which the National Media Museum will be a centrepiece.”

The Council’s leader, David Green, said the departmental move could provide stronger funding for the museums, having joined his counterparts in York and Manchester for talks with leaders from the Group last week.

“We have three weeks to put forward our argument and lobby hard,” he said.

“There is a threat to the whole Science Museum Group if the government go ahead with the level of cuts being talked about.

“We will fight to keep the museum open in Bradford and we have been working with the museum director to see how to boost those numbers.

"I think locals are recognising if we don’t use it there is potential we will lose it.”